A workaround is to prefetch classes on startup to avoid conflicts due to attempts to load the same classes in multiple threads. The following org.jboss.mx.loading.ClassPreloadService was added to 4.0.3SP1, and can be added to either the conf/jboss-service.xml to preload all jboss classes, or a deployment to load its classes. The mbean fragment in the javadoc illustrates how the server can be deployed.

4.0.4+ Updates

As of the 4.0.4 release, the ClassPreloadService has been expanded to support includes/excludes attributes that allow more control over which classes in its classpath are loaded. The new sample mbean/xmbean descriptor is: